Difficulty in knnclassify function

Hey guys i am using knnclassify funnction for 2 images my code is

clear all
a=imread('cameraman.tif');
b=imread('tire.tif');
size(a)
k=zeros(256,256);
[r c]=size(b);
for i=1:r
    for j=1:c
        k(i,j)=b(i,j);
    end
end
group=[1;2;3];
sample=a;
training=k;
Class = knnclassify(sample,training,group);

but i am getting an error which says

??? Undefined function or method 'grp2idx' for input arguments of type 'double'.

Error in ==> knnclassify at 81
[gindex,groups] = grp2idx(group);

Error in ==> lstalgo at 20
Class = knnclassify(sample,training,group);

please help me with it.

Answer 1

[Walter Roberson]

knnclassify seems to be part of the bioinfo toolbox, but grp2idx seems to be part of the stats toolbox. The stats toolbox is a requirement for bioinfo toolbox; see http://www.mathworks.com/products/bioinfo/requirements.html . If you do not have the stats toolbox installed, you need to install (and license) it.